Mastering ChatGPT (OpenAI)ChatGPT foundations · Lesson 2 of 19

Prompting fundamentals that work in ChatGPT

Article · 14 min · 9 min lecture

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Prompting fundamentals that work in ChatGPT

16 chapters · about 9 min · full transcript

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Chapter 1 of 16

Prompting that works

  • Role
  • Goal
  • Constraints
  • Format

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Chapters

The R-G-C-F structure

For any prompt that matters, give ChatGPT four things:

  • Role / context: who you are, who the audience is, the situation. ("I'm the marketing lead at a UK online bakery; this goes to wholesale buyers.")
  • Goal: the one job you want done, stated plainly.
  • Constraints: length, tone, spelling, what to avoid, facts that must not change, compliance rules.
  • Format: the output shape: table with named columns, email with subject line, bullets, JSON.

Current GPT models follow instructions closely, so be explicit. If you want options, ask for options. If you want no preamble, say "no preamble". If a rule matters, say why it matters.

Delimiters and examples

Separate pasted materials with clear delimiters and labels:

### Brief
Launch of our Eid gift hampers, UAE and KSA, three price points.

### Brand rules
Warm, respectful tone. No discount language in week one. English and Arabic.

### Approved past posts
1) ...
2) ...

Task: Write 5 Instagram captions following the brand rules, in the style of
the approved posts. Return a table: Caption (EN) | Caption (AR) | CTA | Rule check.

Few-shot prompting (showing one or two examples of the output you want) is the strongest steering tool. Say what to copy (structure, tone, length) and what not to copy (specific facts).

Ask it to ask

End important prompts with: "Ask me up to three questions before you start if anything important is missing." This reduces guessing and invented details more than any clever phrasing.

Iterate precisely

  • Edit your original message when you realise you left out context; the conversation branches from the improved prompt.
  • Give editor-style feedback when the draft is close: "Keep the structure. Cut to 120 words. Replace the second paragraph with a customer example."
  • Regenerate only when the prompt was good and you want a genuinely different alternative.
  • Start a new chat when a long conversation has drifted, with a short summary of decisions so far.

Formats that save time downstream

Ask for outputs you can paste straight into other tools:

  • "A table I can paste into Google Sheets: Date | Platform | Hook | Caption | CTA."
  • "A CSV with headers name,email_subject,body."
  • "Markdown with H3 headings for our CMS."
  • "A checklist with checkboxes."

Worked example: from vague to usable

Vague: "Write an email to wholesale customers about our new range."

R-G-C-F:

Role/context: I run a small artisan bakery in Leeds that supplies 40 cafés.
Audience: café owners who reorder weekly; they read email on their phones.
Goal: Announce our new gluten-free range and get them to add one item to next week's order.
Constraints: 120-150 words; British spelling; friendly, not salesy; don't claim
"coeliac-safe" (we're not certified); include order cut-off "Thursday 2pm".
Format: subject line (under 45 characters), preview text, body, one-line P.S.
Ask me up to 3 questions first if anything important is missing.

ChatGPT asked for the product names and prices, then produced a draft that needed one edit. Note the compliance constraint: it prevents a claim the bakery cannot substantiate.

Hands-on: your prompt library

  1. Create a document called Prompt library.
  2. Rewrite your three most-used prompts with R-G-C-F, delimiters and one example each.
  3. Run old and new versions and compare the edit time.
  4. Save the winners. You will reuse them in Projects and custom GPTs.

Breaking big jobs into stages

For anything longer than a page, split the work into stages you approve one at a time:

  1. Outline: "Propose three angles and an outline. Don't draft yet."
  2. Draft: "Draft section 1 only, using the approved outline."
  3. Critique: "Review as a sceptical buyer; list the five biggest weaknesses; don't rewrite."
  4. Revise: "Fix weaknesses 1, 2 and 4. Keep everything else."
  5. Package: "Give me a subject line, a 40-word summary and a table version for Sheets."

Each stage is small enough to check properly, and a mistake in the outline costs seconds rather than a full rewrite. Save the stage prompts together in your library as a reusable "long document" recipe.

Reusable prompt template

Role/context: [who I am, audience, situation, why it matters]
Goal: [one job]
Constraints: [length, tone, spelling, must-not-change facts, compliance rules]
Format: [exact output shape]
Examples: [1-2 labelled examples, with what to copy]
Ask me up to 3 questions first if anything important is missing.

Pitfalls

  • Contradictory constraints ("comprehensive, under 40 words").
  • One giant prompt for a multi-stage job; break it into outline, draft, critique, revise.
  • Negative-only instructions; say what to do instead.
  • Pasting passwords, card data or confidential client information.

How to measure success

More first drafts you can use with light edits, fewer back-and-forth turns, and a growing library of prompts your team reuses.

Key takeaways

  • Use Role/context, Goal, Constraints and Format for important prompts.
  • Separate pasted materials with delimiters and include examples of good output.
  • Edit the original prompt to fix gaps; regenerate only for fresh alternatives.
  • Ask for structured formats such as tables that you can paste into other tools.

Check your understanding

Quick questions to lock in the lesson. They don’t count towards your certificate.

  1. What is 'few-shot prompting'?
  2. You realise your original prompt left out the audience. What is the most effective fix?
  3. You need a content plan you can paste straight into Google Sheets. What should you ask for?

Put it into practice

Rewrite three prompts you used this month using R-G-C-F with one example each. Compare the before and after outputs.

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